1. Field of the Invention
The present invention relates to a liquid dosing or metering device for compressed air tools, wherein the device includes a sealable liquid tank whose lower part is connected to the compressed air inlet on the tool, downstream of its throttle valve, via a flow-restricting or flow-impeding filter element that is in contact with the liquid.
2. Description of the Related Art
Such metering devices are intended to supply a usually very small amount of liquid, normally a suitable oil, to the compressed air inlet downstream of the throttle valve in the event of an interruption in the operation of a compressed air tool. When operation is resumed, this liquid is entrained by the compressed air into the tool. It is difficult to avoid undesirable leakage of the liquid from the tank to the air inlet if there is a long interruption in operation. Moreover, it is difficult to provide, regardless of the liquid level, the desired uniform liquid dosage to the air inlet with every interruption in operation.